Fall 2008 Design Projects
We began the semester trying out set-ups for a double width sed tank because the Gracias community required a flowrate much higher than the previous designs. The results can be seen below.
It was ultimately decided that Gracias would have a triple width sed tank. The variable widths of the sed tank will later be automated to account for higher flowrates.
Feedback from the interns in Honduras has shown that settling is occurring in the slopes at Marcala. This is thought to be occurring because the bottom angle is too shallow and because the exit velocity from the slopes is too low. Some literature review showed that to prevent settling and floc break up, the velocity should be around 5 cm/s. The lower angle for future designs was changed from 10 deg to 30-40 deg.
An algorithm was needed to automate the design of the slopes. After several versions, it was decided that exit ports would be needed at the slope exit. A description of this algorithm can be found here.